Vehicle periphery monitor

ABSTRACT

A front camera for filming an area stretching forwards is disposed in a front portion of a vehicle. A side camera for filming an area stretching laterally and diagonally forwards is disposed in a lateral-left portion of the vehicle. An indicator display that can be visually recognized by a driver is disposed in a compartment of the vehicle. An amount of change in the direction of the vehicle, that is, a deflection angle of the vehicle is detected on the basis of a vehicle speed and a steering angle of a steering wheel, which have been detected by means of various sensors. After the indicator display has started displaying a lateral photo image filmed by the side camera, the photo image displayed by the indicator display is shifted from the lateral photo image filmed by the side camera to a front photo image filmed by the front camera if the deflection angle has reached a predetermined angle.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2001-346603 filed onNov. 12, 2001, including the specification, drawings, and abstract isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a vehicle periphery monitor for monitoring theperiphery of a vehicle.

2. Description of the Related Art

In general, as disclosed in Japanese Patent Laid-Open Application No.2000-172996, there is a vehicle periphery monitor having an indicatordisplay for selectively or synthetically displaying a plurality of photoimages representing different areas surrounding a vehicle. This monitoris provided with a plurality of cameras disposed in front and rearportions of the vehicle, and can capture a plurality of photo imagesrepresenting different areas surrounding the vehicle. This monitor has aswitch that can be operated by the driver.

In the aforementioned vehicle periphery monitor, if the driver selects a“pull-over-to-the-left” switch for pulling the vehicle over to the leftfor example, the indicator display displays a photo image representing afront-left area or a rear-left area. If the driver shifts a shift leverto an “R” range under a situation in which the “pull-over-to-the-left”switch has been selected, the indicator display displays a photo imageobtained by synthesizing a front-left photo image and a rear-left photoimage. Thus, in the aforementioned vehicle periphery monitor, theindicator display displays a photo image representing an area requiredby the driver. Hence, the driver is allowed to confirm, for example,whether or not the vehicle has approached an obstacle, by having aglance at the indicator display. As a result, the driver can beguaranteed of safe driving.

However, the photo image displayed by the indicator display of theaforementioned vehicle periphery monitor is selected through a switchingoperation performed by the driver. Hence, in an attempt to suitablycheck safety or the like by looking at the indicator display, the driveris confronted with an increase in operational burden. For example, whenthe vehicle enters a narrow road by making a right or left turn, it isprobable that a photo image representing an area beside the vehicle bedisplayed by the indicator display at an initial stage of the turn so asto allow the driver to confirm whether or not there is any risk that theside of a vehicle hits, and that a photo image representing an area infront of a corner of the vehicle be displayed by the indicator displayat a late stage of the turn so as to allow the driver to confirm whetheror not the front portion of the vehicle has come into contact withsomething. In this case, the aforementioned vehicle periphery monitorrequires the driver to perform a switching operation for shifting photoimages while making the turn. Hence, the driver is confronted with anexcessive increase in operational burden.

It is also possible that photo images representing different areas thatare to be mutually shifted (i.e., the photo image representing the areabeside the vehicle and the photo image representing the area in front ofthe corner of the vehicle in the aforementioned example) besimultaneously displayed by the indicator display. According to thismethod, the photo images displayed by the indicator display are small insize, and the manner in which these photo images are displayed iscomplicated. Hence, the driver has difficulty in instinctivelyrecognizing a situation surrounding the vehicle. As a result, the driveris confronted with a reduction in visibility and has trouble in drivingthe vehicle appropriately.

SUMMARY OF THE INVENTION

It is an object of the invention to construct a vehicle peripherymonitor capable of informing a driver of a situation surrounding avehicle upon request without causing an increase in operational burdenor a reduction in visibility to the driver.

A vehicle periphery monitor in accordance with a first aspect of theinvention comprises a controller for causing an indicator display thatcan be visually recognized by a driver to selectively display a firstphoto image representing an area beside a vehicle (hereinafter referredto as a lateral photo image) or a second photo image representing anarea different from the first photo image. The controller automaticallymakes a shift from one of the first and second photo images to the otherupon fulfillment of a predetermined condition and causes the indicatordisplay to display the other photo image.

In the vehicle periphery monitor in accordance with the first aspect ofthe invention, the second photo image may be a photo image representingan area in front of the vehicle. In the vehicle periphery monitor inaccordance with the first aspect of the invention, the controller mayshift the photo image displayed by the indicator display from thelateral photo image to the front photo image if it is determined that adeflection angle has reached a predetermined angle under a situation inwhich the indicator display displays the lateral photo image.

In the vehicle periphery monitor in accordance with the first aspect ofthe invention, if the deflection angle of the vehicle has reached thepredetermined angle under a situation in which the indicator displaydisplays the lateral photo image, the photo image displayed by theindicator display is shifted from the lateral photo image to the frontphoto image. That is, after the display of the lateral photo image atthe initial stage of a turn, the front photo image is displayed if theturn has continued for a certain period. According to this construction,while the driver drives the vehicle into a narrow road by making a rightor left turn for example, it is possible to inform the driver of asituation beside the vehicle at the initial stage of the turn, forexample, for the purpose of allowing the driver to confirm whether ornot there is any risk that the side of a vehicle hits, and to inform thedriver of a situation in front of the vehicle at the late stage of theturn for the purpose of allowing the driver to confirm a gap between alateral wall on the narrow road and the vehicle. According to the firstaspect of the invention, it is possible to inform the driver of asituation surrounding the vehicle upon request and to keep the driveralert when making a turn, without causing an increase in operationalburden or a reduction in visibility to the driver.

In the aforementioned first aspect, the controller may determine whetheror not the deflection angle has reached the predetermined angle, on theassumption that the vehicle is in a reference state when the indicatordisplay starts displaying the lateral photo image. This makes itpossible to suitably set the timing for a shift between the lateralphoto image and the front photo image as a timing when the vehicle ishighly likely to come into contact with an obstacle or the like.

In the aforementioned first aspect, the controller may determine whetheror not the deflection angle has reached the predetermined angle, on thebasis of a yaw angle generated by the vehicle.

Furthermore, in the aforementioned first aspect of the invention, thecontroller may determine whether or not the deflection angle has reachedthe predetermined angle, on the basis of a relationship between asteering angle generated by the vehicle and a running distance. If thevehicle has covered a certain distance while maintaining a steeringangle equal to or larger than a certain angle, the vehicle is deflectedby a certain angle or more with respect to its initial state. Hence, inthe aforementioned first aspect of the invention, the controller maydetermine that the deflection angle has reached the predetermined angle,if the vehicle has continuously covered a predetermined distance withthe steering angle being equal to or larger than a predetermined angle.

In the aforementioned first aspect of the invention, the controller maycause the indicator display to display in a superimposed manner apredicted travel locus that is estimated to be traced by the vehiclewhen the indicator display displays the front photo image upon a shiftfrom the lateral photo image.

In this case, the predicted travel locus may be an outer-wheel predictedtravel locus that is estimated to be traced by outer wheels of thevehicle.

Further, the indicator display may display in a superimposed manner apredicted travel locus that is estimated to be traced by the vehiclewhen the indicator display displays the lateral photo image. In thiscase, the predicted travel locus may be an inner-wheel predicted travellocus that is estimated to be traced by inner wheels of the vehicle.Thus, if the predicted travel locus that is estimated to be traced bythe vehicle is displayed in a superimposed manner when the indicatordisplay displays the front photo image or the lateral photo image, it ispossible to allow the driver to grasp a positional relationship betweenthe vehicle and an obstacle or the like by having a glance at theindicator display, without causing an increase in operational burden tothe driver.

In the aforementioned first aspect of the invention, the lateral photoimage may be a photo image representing an area beside the vehicle onthe other side of a driver seat. Thus, the driver can be informed of asituation beside the vehicle on the other side of the driver seat,despite the fact that the area beside the vehicle on the other side ofthe driver seat is less visible from the driver than the area beside thevehicle on the side of the driver seat.

Further, in the aforementioned first aspect of the invention, it is alsoappropriate that a first camera disposed in a front portion of thevehicle and having an optical axis oriented toward an area in front ofthe vehicle be provided to film the area in front of the vehicle, that asecond camera disposed in a lateral portion of the vehicle and having anoptical axis oriented toward an area beside the vehicle be provided tofilm the area beside the vehicle, and that the controller cause theindicator display to selectively display the front photo image filmed bythe first camera or the lateral photo image filmed by the second camera.

A vehicle periphery monitor in accordance with a second aspect of theinvention comprises a controller capable of causing an indicator displaythat can be visually recognized by a driver to display a first photoimage (hereinafter referred to as a lateral photo image) representing anarea beside the vehicle. The controller causes the indicator display todisplay the lateral photo image if a steering angle has reached a firstangle. The controller stops the indicator display from displaying thelateral photo image if the steering angle has reached and then droppedbelow a second angle that is larger than the first angle.

In the second aspect of the invention, the indicator display displaysthe lateral photo image if the steering angle of the vehicle has reachedthe first angle. Hence, the driver can be provided at an early timing inadvance with a photo image of an area stretching in a direction alongwhich the vehicle travels while making a turn, without causing anincrease in operational burden or a reduction in visibility to thedriver. If the steering angle of the vehicle has reached and thendropped below a second angle that is larger than the first angle, theindicator display stops displaying the lateral photo image. If thesteering angle has temporarily increased and then decreased, it can bedetermined that the vehicle makes a shift from a state of turning to astate of traveling straight ahead. The demand to monitor the area besidethe vehicle falls. Accordingly, the invention makes it possible toinform the driver of a situation beside the vehicle during a turn, at anearly timing and for a required period.

In this case, in the second aspect of the invention, the controller mayalso stop the indicator display from displaying the lateral photo imageif the lateral photo image remains displayed by the indicator displayfor a predetermined period. Thus, it is possible to prevent the lateralphoto image from being continuously displayed due to the steering anglethat has not reached the second angle yet after having reached the firstangle, without imposing an operational burden on the driver.

In the second aspect of the invention, it is appropriate that thecontroller cause the indicator display to selectively display thelateral photo image or the front photo image representing the areadifferent from the lateral photo image, namely, the area in front of thevehicle, and that the controller cause the indicator display to displaythe front photo image if the indicator display has stopped displayingthe lateral photo image. Thus, while the driver can be provided at anearly timing in advance with a photo image of an area stretching in adirection along which the vehicle travels during a turn, the driver canbe provided at an early timing in advance with a photo image of an areastretching in a direction along which the vehicle travels straight aheadat a late stage of the turn, without causing an increase in operationalburden or a reduction in visibility to the driver.

A vehicle periphery monitor in accordance with a third aspect of theinvention comprises a controller for causing an indicator display thatcan be visually recognized by a driver to selectively display a firstphoto image representing an area beside a vehicle (hereinafter referredto as a lateral photo image) or a front photo image representing an areadifferent from the first photo image, namely, an area in front of thevehicle. The controller causes the indicator display to temporarilydisplay the front photo image if a predetermined time has elapsed undera situation in which the indicator display displays the lateral photoimage.

In the aforementioned third aspect of the invention, the indicatordisplay temporarily displays the front photo image if the predeterminedtime has elapsed under the situation in which the indicator displaydisplays the lateral photo image. According to this construction, thedriver can be temporarily informed of a situation in front of thevehicle while being informed of a situation beside the vehicle, withoutcausing an increase in operational burden or a reduction in visibilityto the driver. Thus, by keeping the driver alert for the area in frontof the vehicle as well, the driver can be prevented from focusing toomuch attention on the area beside the vehicle.

A vehicle periphery monitor in accordance with a fourth aspect of theinvention comprises a controller capable of causing an indicator displaythat can be visually recognized by a driver to display a first photoimage representing an area beside a vehicle (hereinafter referred to asa lateral photo image). The controller causes the indicator display totemporarily display the lateral photo image if it is determined that thevehicle has become ready to take off and that the steering angle isequal to or larger than the predetermined angle.

In the vehicle periphery monitor as the fourth aspect of the invention,the indicator display temporarily displays the lateral photo image ifthe vehicle has become ready to take off with the steering angle beingequal to or larger than the predetermined angle. According to thisconstruction, the driver can be informed of a situation beside thevehicle as a dead area during takeoff with a large steering angle,without causing an increase in operational burden or a reduction invisibility to the driver. Thus, by keeping the driver alert for the deadarea, the driver is allowed to check the security of the areasurrounding the vehicle.

A vehicle periphery monitor in accordance with a fifth aspect of theinvention comprises a controller for causing an indicator display thatcan be visually recognized by a driver to selectively display a firstphoto image representing an area beside a vehicle (hereinafter referredto as a lateral photo image) or a traveling-direction photo imagerepresenting an area different from the lateral photo image, namely, anarea in front of or behind the vehicle. The controller causes theindicator display to temporarily display the traveling-direction photoimage and the lateral photo image in a predetermined order if it isdetermined that the vehicle has become ready to take off.

In the fifth aspect of the invention, if the vehicle has become ready totake off, the indicator display temporarily displays thetraveling-direction photo image and the lateral photo image in apredetermined order. According to this construction, the driver can beinformed of an overall situation of an area surrounding the vehicleduring takeoff, without causing an increase in operational burden or areduction in visibility to the driver. Thus, by keeping the driver alertfor the dead area, the driver is allowed to check the security of thearea surrounding the vehicle.

In the aforementioned fourth and fifth aspects of the invention, thecontroller may determine that the vehicle has become ready to take off,if a shift position of the vehicle has shifted from a non-drive positionto a drive position or has shifted from one forward or backward driveposition to the other forward or backward drive position.

In the aforementioned fourth and fifth aspects of the invention, thecontroller may determine that the vehicle has become ready to take off,if a braking operation has been performed with the vehicle beingstopped.

In the first to fifth aspects of the invention, “the lateral photoimage” may include a photo image representing a continuous areaextending from a lateral portion to a front portion of the vehicle, inaddition to the photo image representing the area beside the vehicle.Further, in the first to fifth aspects of the invention, “the steeringangle of the vehicle” may be a steering angle actually formed by wheelsor a steering angle actually formed by a steering wheel operated by thedriver.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further objects, features and advantages of theinvention will become apparent from the following description ofpreferred embodiments with reference to the accompanying drawings,wherein like numerals are used to represent like elements and wherein:

FIG. 1 is a system configuration view of a vehicle periphery monitor inaccordance with a first embodiment of the invention.

FIG. 2A and FIG. 2B show areas to be filmed by cameras of the vehicleperiphery monitor in accordance with the first embodiment.

FIG. 3 schematically shows a situation in which a vehicle travels fromone road into another road by making a left turn.

FIG. 4 is a flowchart of a control routine that is executed to shiftphoto images displayed by an indicator display in the first embodiment.

FIG. 5A and FIG. 5B show in a time-series manner photo images displayedby the indicator display when a side camera is required under thesituation shown in FIG. 3.

FIG. 6 is a flowchart of a control routine that is executed to shiftphoto images displayed by the indicator display in a second embodimentof the invention.

FIG. 7 is a flowchart of a control routine that is executed to shiftphoto images displayed by the indicator display in a third embodiment ofthe invention.

FIG. 8 is a flowchart of a control routine that is executed to shiftphoto images displayed by the indicator display in a fourth embodimentof the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a system configuration of a vehicle periphery monitor 20 inaccordance with a first embodiment of the invention. In this embodiment,a vehicle equipped with the vehicle periphery monitor 20 has frontwheels as turnable wheels that are turned in accordance with a steeringoperation performed by the driver and rear wheels as non-turnablewheels. The vehicle periphery monitor 20 has a monitor-purposeelectronic control computer (hereinafter referred to simply as “acomputer”) 22. The computer 22 controls the vehicle periphery monitor20.

A shift position sensor 24, a steering angle sensor 26, and a vehiclespeed sensor 28 are connected to the computer 22. The shift positionsensor 24 outputs a signal corresponding to a position of a gear-shiftlever operated by the driver. The steering angle sensor 26 outputs asignal corresponding to a steering angle δ of a steering wheel operatedby the driver. The vehicle speed sensor 28 generates a pulse signal atintervals of a period corresponding to a vehicle speed SPD. The signalsoutput from the shift position sensor 24, the steering angle sensor 26,and the vehicle speed sensor 28 are supplied to the computer 22.

The computer 22 detects a position of the gear-shift lever on the basisof an output signal of the shift position sensor 24, detects a steeringangle δ on the basis of an output signal of the steering sensor 26, anddetects a vehicle speed SPD on the basis of an output signal of thevehicle speed sensor 28. It is assumed herein that the steering angle δis positive when the steering wheel has been turned to the left (i.e.,counterclockwise) and that the steering angle δ is negative when thesteering wheel has been turned to the right (i.e., clockwise).

The computer 22 determines on the basis of a position of the gear-shiftlever whether or not the wheels are coupled with power (i.e., whether ornot the vehicle is in a driven state) or whether or not the wheels areuncoupled with power (i.e., whether or not the vehicle is in anon-driven state). If the vehicle is in a coupled state, the computer 22further determines whether or not the vehicle is moving forwards orwhether or not the vehicle is moving backwards. The computer 22estimates a turning radius occurring in the vehicle on the basis of thesteering angle δ and the vehicle speed SPD, detects a position of thepertinent vehicle with respect to a reference position, and detects anamount of change in the direction of the vehicle (i.e., deflection angleθ). It is assumed herein that the deflection angle θ is positive whenthe vehicle is directed to the left (i.e., counterclockwise) from areference direction and that the deflection angle θ is negative when thevehicle is directed to the right (i.e., clockwise) from the referencedirection. The computer 22 calculates a predicted travel path (guidanceroute) which is estimated to be covered when the vehicle moves forwardsor backwards, on the basis of a turning radius estimated on the basis ofthe steering angle δ.

A back camera 30 disposed at a center of a door of a vehicle rearportion, a front camera 32 disposed at a center of a grille of a vehiclefront portion, and a side camera 34 disposed in a lateral portion on theother side of the driver seat of the vehicle (e.g., in a door mirrorstay) are connected to the computer 22. It is also appropriate that theback camera 30 and the front camera 32 be disposed on a bumper or thelike in the vehicle rear portion or the vehicle front portion. Further,it is also appropriate that the side camera 34 be disposed in a lateralportion other than the door mirror stay.

FIG. 2A and FIG. 2B show areas filmed by the cameras 30 to 34 in thefirst embodiment. It is to be noted herein that the areas filmed by thecameras 30 to 34 are indicated by diagonal lines in FIG. 2A and FIG. 2B.As shown in FIG. 2A and FIG. 2B, the back camera 30 has an optical axisoriented backwards from the vehicle rear portion, and films apredetermined area stretching backwards therefrom, including a dead areainvisible from the driver. The front camera 32 has an optical axisoriented forwards from the vehicle front portion, and films apredetermined area stretching forwards therefrom, including a dead areainvisible from the driver. The side camera 34 has an optical axisoriented sidewards and diagonally forwards from a vehicle lateralportion, and films a predetermined area stretching in that direction,including a dead area invisible from the driver. The images filmed bythe cameras 30 to 34 (hereinafter referred to as a rear photo image, afront photo image, and a lateral photo image respectively) are suppliedto the computer 22.

As shown in FIG. 1, an indicator display 40 is connected to the computer22. The indicator display 40 is disposed in a console or the like in acompartment so as to ensure visibility of the driver. The computer 22selects one of a rear photo image filmed by the back camera 30, a frontphoto image filmed by the front camera 32, and a lateral photo imagefilmed by the side camera 34 in accordance with a regulation to bedescribed later, and drives the indicator display 40 so that theselected image is displayed by the indicator display 40.

A back camera request switch 50, a front camera request switch 52, and aside camera request switch 54 are also connected to the computer 22.Hereinafter, when generically describing the back camera request switch50, the front camera request switch 52, and the side camera requestswitch 54, they will be referred to simply as the request switches 50 to54. The request switches 50 to 54 are disposed in the console or thelike in the compartment so as to be operable by the driver. For example,it is appropriate that the request switches 50 to 54 be designed toappear in a touch-panel manner on a screen of the indicator display 40.

The back camera request switch 50 is a switch that outputs a signalcorresponding to whether or not the driver requests a rear photo imagefilmed by the back camera 30 to be displayed by the indicator display40. The front camera request switch 52 is a switch that outputs a signalcorresponding to whether or not the driver requests a front photo imagefilmed by the front camera 32 to be displayed by the indicator display40. The side camera request switch 54 is a switch that outputs a signalcorresponding to whether or not the driver requests a lateral photoimage filmed by the side camera 34 to be displayed by the indicatordisplay 40. The output signals of the request switches 50 to 54 aresupplied to the computer 22. The computer 22 specifies an imagerequested by the driver to be displayed by the indicator display 40, onthe basis of the output signals of the request switches 50 to 54.

A timer 58 is built into the computer 22. The timer 58 counts a timestarting from a timing when a photo image on the indicator display 40 isfirst displayed through the request switches 50 to 54 or throughfulfillment of a predetermined condition by a vehicle state as will bedescribed later (also including a time after a shift from an imagefilmed by one camera to an image filmed by another camera). The computer22 performs predetermined processings on the basis of a value counted bythe timer 58, as will be described later.

Next, the operation of the vehicle periphery monitor 20 in accordancewith the first embodiment will be described.

In the first embodiment, in principle, the computer 22 causes theindicator display 40 to display a photo image requested by the driverand specified on the basis of the output signals of the back camerarequest switch 50, the front camera request switch 52, and the sidecamera request switch 54. When a rear photo image is displayed by theindicator display 40, the image appears laterally inversed with respectto an image actually filmed by the back camera 30, so as to enhancevisibility of the driver.

As described above, the vehicle of the first embodiment has the frontwheels as turnable wheels and the rear wheels as non-turnable wheels.Hence, whether the vehicle is making a turn while moving forwards orbackwards, the turn-wise inner rear wheel moves along the innermost path(with a minimum radius) and the turn-wise outer front wheel moves alongthe outermost path (with a maximum radius). In view of this respect,when helping the driver operate the vehicle, it is appropriate that alocus estimated to be actually traced by the turn-wise inner rear wheelmoving with the minimum radius (hereinafter referred to as aninner-wheel predicted travel locus) and a locus estimated to be actuallytraced by the turn-wise outer front wheel moving with the maximum radius(hereinafter referred to as an outer-wheel predicted travel locus) bedisplayed in a superimposed manner by the indicator display 40 wherephoto images filmed by the cameras 30 to 34 are displayed.

Thus, in the first embodiment, the computer 22 calculates an inner-wheelpredicted travel locus X and an outer-wheel predicted travel locus Y onthe basis of a turning radius, conforms the inner-wheel predicted travellocus X and the outer-wheel predicted travel locus Y with photo imagesfilmed by the cameras 30 to 34, and displays in a superimposed mannerthose travel loci X, Y by means of the indicator display 40 where thephoto images are displayed. It is also appropriate herein that thecomputer 22 cause the indicator display 40 to display in a superimposedmanner an elongation representative of vehicle width (hereinafterreferred to as vehicle width elongation) which is determined from apositional relationship among the cameras 30 to 34 and a body of thevehicle. In this case, the inner-wheel predicted travel locus X, theouter-wheel predicted travel locus Y, and the vehicle width elongation Zare displayed by the indicator display 40 in mutually different shapes,colors, or the like.

It is to be noted herein that display of a lateral photo image filmed bythe side camera 34 on the indicator display 40 is requested by operatingthe side camera request switch 54 mainly in the following cases where:(a) the driver confirms a situation in the periphery laterally leftwardof the vehicle, for example, at the time of takeoff; (b) the driverconfirms a distance to be covered when pulling the vehicle over toward aleft wall; and (c) the driver confirms whether there is any risk thatthe side of a vehicle hits when making a left turn.

FIG. 3 schematically shows a situation in which a vehicle travels from aroad 82 into a narrow road 84 by making a left turn. It is assumedherein that a lateral wall 86 exists beside the road 82, that lateralwalls 88, 89 exist beside the road 84, and that the lateral walls 86, 88form a corner 92. FIG. 3 also shows locations (1), (2), and (3) that aresequentially passed by the vehicle 80 when making a left turn andentering the road 84.

In order for the vehicle 80 to suitably travel from the road 82 into theroad 84 by making a left turn, the driver is required to first confirmthe possibility that the side of a vehicle hits due to a differencebetween the turn-wise inner front and rear wheels and a gap between alateral-left portion of the vehicle 80 and the corner 92 (indicated by Oin FIG. 3), and then to confirm, after duration of the turning, a gapbetween a front-right position of the vehicle 80 and a lateral wall 90(indicated by O in FIG. 3). In this respect, in the aforementioned case(c), it is not appropriate that a lateral photo image that has beendisplayed by the indicator display 40 through operation of the sidecamera request switch 54 remain as it is for a long time. That is, if alateral photo image remains displayed by the indicator display 40despite continuation of the turning of the vehicle, the driver is unableto confirm the gap between the front-right portion of the vehicle 80 andthe lateral wall 90 by having a glance at the indicator display 40. As aresult, there is a risk of the front-right portion of the vehicle 80coming into contact with the lateral wall 90.

Thus, if the vehicle continues to turn even in the case where a lateralphoto image has been displayed by the indicator display 40 throughoperation of the side camera request switch 54, the vehicle peripherymonitor 20 of the first embodiment is characterized in shifting thephoto image displayed by the indicator display 40 from a lateral photoimage filmed by the side camera 34 to a front photo image filmed by thefront camera 32 at a suitable timing so as to confirm a gap between thefront-right portion of the vehicle 80 and an obstacle such as thelateral wall 90, without requiring the driver to perform any operation.This characteristic part will be described hereinafter.

In the situation shown in FIG. 3, the driver must determine whetherthere is the possibility that the side of a vehicle hits on theturn-wise inner side when the vehicle 80 is located substantiallyparallel to the road 82 immediately before making a left turn into theroad 84 (the state indicated by (1) in FIG. 3). The driver must alsoconfirm there is a gap between the lateral-left portion of the vehicleand the corner 92 when the vehicle 80 has actually traveled from theroad 82 into the road 84 (the state indicated by (2) in FIG. 3).Furthermore, the driver must confirm a gap between the front-rightportion of the vehicle 80 and the lateral wall 90 when the vehicle 80has continued to turn for a certain period (the state indicated by (3)in FIG. 3).

Accordingly, if the indicator display 40 starts displaying a lateralphoto image filmed by the side camera 34 through operation of the sidecamera request switch 54 performed by the driver so as to determinewhether the side of a vehicle hits in the aforementioned case (c), thelateral photo image remains displayed until the vehicle 80 turns toalmost pass the corner 92. If the vehicle reaches such a turning state,a shift to a front photo image filmed by the front camera 32 is made.Thus, it becomes possible to permit the driver to confirm a gap formedby the lateral-left portion of the vehicle 80 and the corner 92 and toconfirm a gap between the front-right portion of the vehicle 80 and anobstacle such as the lateral wall 90 at a suitable timing, withoutrequiring the driver to perform any operation.

If a positional relationship between the vehicle 80 and the corner 92 isthe same when the driver starts confirming the possibility that the sideof a vehicle hits, the amount of change in direction of the vehicle 80(i.e., deflection angle θ) is substantially constant from the start ofthe confirmation until the vehicle 80 passes the corner 92. Thus, inshifting the photo image displayed by the indicator display 40 from alateral photo image filmed by the side camera 34 to a front photo imagefilmed by the front camera 32 as described above, it is appropriate todetect a deflection angle θ of the vehicle 80 on the assumption that thevehicle is oriented in a reference direction when the display of alateral photo image is started through operation of the side camerarequest switch 54, and to determine whether or not the deflection angleθ has reached a predetermined angle.

In the aforementioned cases (a) and (b) unlike the aforementioned case(c), there is no substantial change in the direction of the vehicle,that is, no increase in the deflection angle θ of the vehicle from atiming when the display of a lateral photo image is started throughoperation of the side camera request switch 54 to a timing when aperipheral situation of an area beside the vehicle is confirmed or whenthe vehicle has been pulled over. Hence, as described, if the photoimage displayed by the indicator display 40 is shifted depending onwhether or not the deflection angle θ of the vehicle 80 has reached apredetermined angle, for example, the photo image displayed by theindicator display 40 is prevented from being shifted when the driverconfirms a peripheral situation of the area beside the vehicle, at thetime of takeoff or when the driver confirms a process of pulling thevehicle over.

FIG. 4 is an exemplary flowchart of a control routine that is executedby the computer 22 in the first embodiment so as to realize theaforementioned functions. The routine shown in FIG. 4 is repeatedlystarted every time processings thereof are terminated. If the routineshown in FIG. 4 is started, the processing in step 100 is firstperformed.

In step 100, it is determined whether or not the front camera requestswitch 52 has been turned on, that is, whether or not the display of afront photo image filmed by the front camera 32 by means of theindicator display 40 has been requested. If the result of thedetermination is positive, the processing in step 102 is then performed.On the other hand, if the result of the determination is negative, theprocessing in step 104 is then performed.

In step 102, the processing of causing the indicator display 40 todisplay a front photo image filmed by the front camera 32 as to an areain front of the vehicle is performed. If the processing in step 102 isperformed, the indicator display 40 thereafter displays a sight in frontof the vehicle 80. If the processing in step 102 is terminated, thepresent routine is terminated.

In step 104, it is determined whether or not the side camera requestswitch 54 has been turned on, that is, whether or not the display of alateral photo image filmed by the side camera 34 by means of theindicator display 40 has been requested. If the result of thedetermination is negative, the present routine is terminated withoutperforming any further processing afterwards. On the other hand, if theresult of the determination is positive, the processing in step 106 isthen performed.

In step 106, it is determined whether or not the deflection angle θ ofthe vehicle 80, which has been detected on the basis of the steeringangle δ detected by the steering angle sensor 26 and the vehicle speedSPD detected by the vehicle speed sensor 28, is smaller than apredetermined angle θ1, on the assumption that the vehicle 80 isoriented in a reference direction when the display of a lateral photoimage is requested through operation of the side camera request switch54. It is to be noted herein that the predetermined angle δ1 is adeflection angle θ of the vehicle 80 from a time when the side camerarequest switch 54 is operated to a time when the vehicle 80 is estimatedto pass the corner 92.

If a relationship θ<θ1 has been established, it can be determined thatthe vehicle 80 has not turned to the extent of passing the corner 92after operation of the side camera request switch 54. In this case, itis appropriate that a lateral photo image filmed by the side camera 34be displayed as requested. Accordingly, if such a determination is made,the processing in step 108 is then performed.

In step 108, the processing of causing the indicator display 40 todisplay a lateral photo image filmed by the side camera 34 as to alateral area of the vehicle is performed. If the processing of this step108 is performed, the indicator display 40 thereafter displays a sightbeside the vehicle 80. If the processing of this step 108 is terminated,the present routine is terminated.

On the other hand, if the relationship θ<θ1 has not been established inthe aforementioned step 106, that is, if a relationship θ≧θ1 has beenestablished, it can be determined that the vehicle 80 has passed thecorner 92, and there is no need to thereafter cause the indicatordisplay 40 to display a lateral photo image filmed by the side camera34. In this case, it is appropriate that the photo image displayed bythe indicator display 40 be thereafter shifted from the lateral photoimage filmed by the side camera 34 to a front photo image filmed by thefront camera 32. Accordingly, if it is determined in the aforementionedstep 106 that the relationship θ<θ1 has not been established, theprocessing of causing the indicator display 40 to display the frontphoto image filmed by the front camera 32 as to the area in front of thevehicle is performed in the aforementioned step 102.

According to the aforementioned routine shown in FIG. 4, under thesituation in which the driver has requested the lateral photo imagefilmed by the side camera 34 to be displayed by the indicator display40, the lateral photo image filmed by the side camera 34 can bedisplayed as requested until the deflection angle of the vehicle 80reaches the predetermined angle θ1 after the request has been made, andthe front photo image filmed by the front camera 32 can be displayedinstead of the lateral photo image after the deflection angle θ hasreached the predetermined angle θ1.

FIG. 5A and FIG. 5B show in a time-series manner photo images to bedisplayed by the indicator display 40 in the case where the side camerarequest switch 54 has been operated under the situation shown in FIG. 3in the first embodiment. Under the situation in which the display of thelateral photo image filmed by the side camera 34 has been requested, ifthe photo images are displayed by the indicator display 40 as shown inFIG. 5A and FIG. 5B, it is possible to cause the driver at an earlystage of a left turn of the vehicle to confirm the possibility that theside of a vehicle hits due to a difference between the turn-wise innerwheels and to confirm a gap between the lateral portion of the vehicle80 and the corner 92. Further, it is also possible to cause the driverat a late stage of the left turn of the vehicle to confirm a gap betweenthe front portion of the vehicle 80 and the lateral wall 90.

In the first embodiment, a shift of the photo image displayed by theindicator display 40 from the lateral photo image to the front photoimage under the situation in which the display of the lateral photoimage filmed by the side camera 34 has been requested is not made on thebasis of an operation performed by the driver. This shift is madethrough a determination made on the monitor side on the basis of thedeflection angle θ of the vehicle 80. Hence, the driver is preventedfrom facing an increase in operational burden in making such a shift ofdisplay. Further, in the first embodiment, there is no chance of thelateral photo image filmed by the side camera 34 and the front photoimage filmed by the front camera 32 being displayed by the indicatordisplay 40 simultaneously. Hence, the driver can instinctively recognizea situation surrounding the vehicle, and the driver is prevented fromlosing visibility.

Further, in the first embodiment, under the situation in which thedriver has requested a lateral photo image filmed by the side camera 34to be displayed by the indicator display 40, the lateral photo imagefilmed by the side camera 34 is displayed as requested until thedeflection angle of the vehicle 80 reaches the predetermined angle θ1after the request has been made, and a front photo image filmed by thefront camera 32 is displayed instead of the lateral photo image afterthe deflection angle θ has reached the predetermined angle θ1. Hence, atiming for a shift between the lateral photo image and the front photoimage can be suitably set as a timing when the vehicle is highly likelyto come into contact with an obstacle or the like.

Thus, according to the vehicle periphery monitor, it is possible toadequately inform the driver of a peripheral situation of a portion ofthe vehicle 80 which tends to contact something, namely, of a peripheralsituation of the vehicle which is wanted by the driver and to whichattention has to be paid when the vehicle 80 makes a left turn, withoutcausing an increase in operational burden or a reduction in visibilityto the driver. Thus, according to the first embodiment, the driver canbe reminded to pay attention so as to ensure safe driving when making aleft turn, and it is possible for the driver to suitably and easilyoperate the vehicle.

If the driver has operated the side camera request switch 54 not toconfirm the possibility that the side of a vehicle hits during a leftturn of the vehicle 80 but to confirm a peripheral situation duringtakeoff or a process of pulling the vehicle over to the left, thedeflection angle θ of the vehicle 80 does not substantially change froma time when the display of the lateral photo image by means of theindicator display 40 is started to a time when confirmation of theperipheral situation is completed or when the process of pulling thevehicle over is completed. In the first embodiment, even in the casewhere the display of the lateral photo image has been started throughoperation of the side camera request switch 54, if the deflection angleθ has not reached the predetermined angle θ1, the lateral photo imageremains displayed. Hence, according to the first embodiment, if the sidecamera request switch 54 has been operated to confirm a peripheralsituation at the time of takeoff or to confirm a process of pulling thevehicle over to the left, the photo image displayed by the indicatordisplay 40 is prevented from being unexpectedly shifted to the photoimage filmed by the front camera 32.

Further, in the first embodiment, if photo images filmed by the cameras30 to 34 are displayed by the indicator display 40, the inner-wheelpredicted travel locus X, the outer-wheel predicted travel locus Y, andthe vehicle width elongation of the vehicle 80 are displayed in asuperimposed manner by the indicator display 40 in accordance with thephoto images as described above.

More specifically, if the lateral photo image filmed by the side camera34 is displayed by the indicator display 40 as shown in FIG. 5A, theinner-wheel predicted travel locus X and the vehicle width elongation Zof the vehicle 80 are displayed in a superimposed manner. It is alsoappropriate herein that an area between the inner-wheel predicted travellocus X and the vehicle width elongation Z be colored on the indicatordisplay 40 as shown in FIG. 5A. According to this construction, if thedriver has requested a lateral photo image filmed by the side camera 34to be displayed when the vehicle 80 makes a right or left turn, it ispossible for the driver to suitably grasp a mutual positionalrelationship between the vehicle 80 and the corner 92. Thus, accordingto the first embodiment, the precision in confirming the possibilitythat the side of a vehicle hits on the turn-wise inner side and theprecision in confirming a gap between the vehicle 80 and the corner 92can be enhanced. As a result, the vehicle can be guaranteed of safedriving when making a right or left turn.

Further, if the front photo image filmed by the front camera 32 isdisplayed by the indicator display 40 as shown in FIG. 5B, theouter-wheel predicted travel locus Y is displayed in a superimposedmanner. This construction makes it possible for the driver to adequatelygrasp a mutual positional relationship between the vehicle 80 and thelateral wall 90 in the case where the driver has requested the lateralphoto image filmed by the side camera 34 to be displayed when thevehicle 80 makes a right or left turn. Thus, according to the firstembodiment, the precision in confirming a gap between the vehicle andthe lateral wall on the turn-wise outer side can be enhanced, and thevehicle can be guaranteed of safe driving when making a right or leftturn.

It is to be noted in the aforementioned embodiment that the inner-wheelpredicted travel locus X and the outer-wheel predicted travel locus Ycorrespond to “the predicted travel locus” mentioned in the claims, thatthe front camera 32 corresponds to “the first camera” mentioned in theclaims, and that the side camera 34 corresponds to “the second camera”mentioned in the claims. Further, the computer 22 performs theprocessings in step 102, step 106, and step 108 in the routine shown inFIG. 4 corresponds to “the controller” mentioned in the claims. Thelateral photo image corresponds to “the first photo image” mentioned inthe claims. The front photo image and the rear photo image correspond to“the second photo image” mentioned in the claims, which is obtained byfilming an area other than the lateral photo image.

In the aforementioned first embodiment, the deflection angle θ of thevehicle is detected on the basis of the steering angle δ of the steeringwheel and the vehicle speed SPD, and the photo image displayed by theindicator display 40 is shifted from the lateral photo image to thefront photo image using the deflection angle θ as a parameter. However,the invention is not limited to this construction. That is, it is alsoappropriate that a yaw angle generated by the vehicle be directlydetected or that a deflection angle θ be detected by integrating anoutput from a yaw rate sensor 29.

Further, in the aforementioned first embodiment, the deflection angle θof the vehicle is detected on the basis of the steering angle δ of thesteering wheel detected by the steering angle sensor 26 and the vehiclespeed SPD detected by the vehicle speed sensor 28, and it is determinedwhether or not the deflection angle θ has reached the predeterminedangle θ1 on the assumption that the vehicle is oriented in a referencedirection when the display of a lateral photo image is started throughoperation of the side camera request switch 54, so as to shift the photoimage displayed by the indicator display 40. It is also appropriate toadditionally determine on the basis of a relationship between thesteering angle δ and running distance whether or not the deflectionangle θ has reached the predetermined angle θ1. If the vehicle covers acertain distance while maintaining a steering angle equal to or largerthan a certain value, the vehicle is deflected by a certain angle ormore with respect to an initial reference state. Hence, it isappropriate to determine that the deflection angle θ has reached thepredetermined angle θ1 if the vehicle has continuously covered apredetermined distance with the steering angle δ thereof being equal toor larger than a predetermined angle. It is also possible to calculate arunning distance on the basis of an output from the vehicle speedsensor.

Next, a second embodiment of the invention will be described withreference to FIG. 6 as well as FIGS. 1 and 2.

In the aforementioned first embodiment, the photo images filmed by thecameras 30 to 34 are displayed by the indicator display 40, inprinciple, through the operation of the request switches 50 to 54performed by the driver. On the other hand, in the second embodiment,while the vehicle is running, photo images filmed by the cameras 30 to34 are selectively displayed by the indicator display 40 in accordancewith a running state of the vehicle, without requiring the driver toperform any operation. In the second embodiment, components identical tothose of the aforementioned construction shown in FIG. 1 are denoted bythe same reference numerals and will not be described again below.

If the steering angle δ is large under the situation in which thevehicle travels forwards, the turning radius of the vehicle is small.The lateral photo image filmed by the side camera 34 often covers alarger area in the traveling direction of the vehicle than the frontphoto image filmed by the front camera 32. If the turning radius issmall, the angular difference between the turn-wise inner wheels isenlarged accordingly. In consideration of this respect, when the vehiclemakes a sharp left turn while moving forwards, the peripheral situationto which the driver has to pay attention is a situation on the left ofthe vehicle. Thus, if the lateral photo image filmed by the side camera34 is displayed by the indicator display 40 in response to an increasein the steering angle δ during the traveling of the vehicle, the drivercan be informed of a situation to which the driver has to pay attentionin the traveling direction of the vehicle. Further, if the turning ofthe vehicle is completed under the situation in which the lateral photoimage filmed by the side camera 34 is displayed by the indicator display40 according to the aforementioned method, the steering angle δdecreases. Hence, the peripheral situation of the vehicle to which thedriver has to pay attention thereafter shifts from the situation on theleft of the vehicle to a situation in front of the vehicle. Thus, if thefront photo image filmed by the front camera 32 is displayed by theindicator display 40 in the case where the steering angle δ hasdecreased after the display of the lateral photo image filmed by theside camera 34 as described above, the driver can be informed of asituation to which the driver has to pay attention in the travelingdirection of the vehicle.

FIG. 6 shows an exemplary flowchart of a control routine that isexecuted by the computer 22 in the second embodiment so as to realizethe aforementioned functions. The routine shown in FIG. 6 is repeatedlystarted every time processings thereof are terminated. If the routineshown in FIG. 6 is started, the processing in step 150 is firstperformed.

In step 150, it is determined whether or not the vehicle speed SPDdetected by means of the vehicle speed sensor 28 is “0”, that is,whether or not the vehicle is in a stopped state. If the vehicle is in astopped state as a result, it is impossible to cause the indicatordisplay 40 to display a photo image in accordance with a travelingdirection of the vehicle. Thus, if the result of this determination ispositive, the processing in step 152 is then performed. On the otherhand, if it is determined that the vehicle is not in a stopped state,the processing in step 154 is then performed.

In step 152, the processing of causing the indicator display 40 todisplay photo images of the cameras 30 to 34 in accordance withoperational states of the back camera request switch 50, the frontcamera request switch 52, and the side camera request switch 54 isperformed. If the processing in step 152 is performed, the indicatordisplay 40 thereafter displays a sight corresponding to a request. Ifthe processing in step 152 is terminated, the present routine isterminated.

In step 154, it is determined whether or not the gear-shift leverdetected by means of the shift position sensor 24 is at a reverseposition “R”. If the gear-shift lever is at the reverse position “R”, itcan be determined that the vehicle is in a state of moving backwards.The area behind the vehicle is often invisible from the driver. Hence,in this case, it is appropriate that the rear photo image filmed by theback camera 30 be displayed by the indicator display 40 regardless ofthe steering angle δ of the steering wheel. Thus, if the result of thisdetermination is positive, the processing in step 156 is then performed.On the other hand, if the gear-shift position is not at the reverseposition “R”, the aforementioned inconvenience is not caused. Thus, ifthe result of this determination is negative, the processing in step 158is then performed.

In step 156, the processing of causing the indicator display 40 todisplay the rear photo image filmed by the back camera 30 as to the areabehind the vehicle is performed. If the processing in step 156 isperformed, the indicator display 40 thereafter displays a sight behindthe vehicle. If the processing in step 156 is terminated, the presentroutine is terminated.

In step 158, it is determined whether or not the steering angle δ of thesteering wheel detected by means of the steering angle sensor 26 issmaller than a predetermined angle δ1. It is to be noted herein that thepredetermined angle δ1 is a steering angle δ at a time immediatelypreceding a time when it can be determined that the lateral photo imagefilmed by the side camera 34 covers a larger area in the travelingdirection of the vehicle than the front photo image filmed by the frontcamera 32. If it is determined that a relationship δ<δ1 has beenestablished as a result, the processing in step 160 is then performed.On the other hand, if it is determined that the relationship δ<δ1 hasnot been established, the processing in step 162 is then performed.

In step 160, the processing of causing the indicator display 40 todisplay the front photo image filmed by the front camera 32 as to thearea in front of the vehicle is performed. If the processing in step 160is performed, the indicator display 40 thereafter displays a sight infront of the vehicle. If the processing in step 160 is terminated, thepresent routine is terminated. Further, in step 162, the processing ofcausing the indicator display 40 to display the lateral photo imagefilmed by the side camera 34 as to the area beside the vehicle isperformed. If the processing in step 162 is performed, the indicatordisplay 40 thereafter displays a sight beside the vehicle. If theprocessing in step 162 is terminated, the processing in step 164 is thenperformed.

In step 164, it is determined whether or not the steering angle δ hasbecome equal to or larger than a predetermined angle δ2 that is largerthan the predetermined angle δ1 after being regarded in theaforementioned step 158 as having reached the predetermined angle δ1,and has thereafter dropped below the predetermined angle δ2. Thepredetermined angle δ2 is a steering angle δ from which it can bedetermined that the lateral photo image filmed by the side camera 34covers a larger area in the traveling direction of the vehicle than thefront photo image filmed by the front camera 32. The predetermined angleδ2 is larger than the aforementioned predetermined angle δ1.

If the steering angle δ further increases and then decreases under thesituation in which the lateral photo image filmed by the side camera 34is displayed, it is possible to determine that the turning of thevehicle is about to end. Hence, the necessity to inform the driver of asituation beside the vehicle decreases, whereas the necessity to informthe driver of a situation in front of the vehicle increases. Thus, if itis determined that the aforementioned condition has been fulfilled, theprocessing in step 160 is then performed, and the processing of shiftingthe photo image displayed by the indicator display 40 from the lateralphoto image filmed by the side camera 34 to the front photo image filmedby the front camera 32 is performed. On the other hand, if it isdetermined that the aforementioned condition has not been fulfilled, theprocessing in step 166 is then performed.

In step 166, it is determined whether or not a time T that has elapsedafter the start of the display of the lateral photo image filmed by theside camera 34 in the aforementioned step 162 has reached apredetermined time T0. It is to be noted herein that the predeterminedtime T0 is set as an average time from a time when the steering angle δof the vehicle becomes equal to or larger than the predetermined angleδ1 through a time when the steering angle δ then becomes equal to orlarger than the predetermined angle δ2 to a time when the steering angleδ drops below the predetermined angle δ2. If it is determined that arelationship T≧T0 has not been established as a result, the processingin the aforementioned step 164 is repeatedly performed. On the otherhand, if the relationship T≧T0 has been established, it is possible todetermine that a sufficient time for displaying the lateral photo imagefilmed by the side camera 34 has continuously elapsed, and it isappropriate that the photo image displayed by the indicator display 40be shifted to the front photo image filmed by the front camera 32. Thus,if the result of this determination is positive, the aforementionedprocessing in step 160 is then performed. The aforementioned routineshown in FIG. 6 makes it possible to cause the indicator display 40 todisplay the photo images corresponding to the request switches 50 to 54while the vehicle is stopped, to cause the indicator display 40 todisplay the rear photo image filmed by the back camera 30 disposed atthe rear portion of the vehicle body when the vehicle moves backwards,to cause the indicator display 40 to display the front photo imagefilmed by the front camera 32 if the steering angle of the steeringwheel is small under the situation in which the vehicle moves forwards,and to cause the indicator display 40 to display the lateral photo imagefilmed by the side camera 34 if the steering angle of the steering wheelis large under the situation in which the vehicle moves forwards.

According to this construction, while the vehicle is traveling, thedriver can be informed of a situation in front of the vehicle where thetraveling direction of the vehicle can be easily recognized if thesteering angle δ is small, whereas the driver can be informed of asituation beside the vehicle where the traveling direction of thevehicle can be easily recognized if the steering angle δ is large. Thus,according to the second embodiment, it is possible to suitably informthe driver, while driving, of a peripheral situation of the vehicle towhich the driver has to pay attention, in accordance with a runningstate of the vehicle, and it is possible to keep the driver alert indriving the vehicle.

In the second embodiment, a so-called hysteresis is set as to athreshold of a parameter for shifting the photo image displayed by theindicator display 40. That is, the condition for starting the display ofa lateral photo image filmed by the side camera 34 is that the steeringangle δ reaches the predetermined angle δ1 which is relatively small,whereas the condition for thereafter starting the display of a frontphoto image filmed by the front camera 32 is that the steering angle δdrops below the predetermined angle δ2 which is relatively large.

Hence, according to the second embodiment, without causing the driver toface an increase in operational burden through reduced operability orvisibility, the driver is informed of a situation beside the vehiclewhere the traveling direction of the vehicle can be easily recognizedfor a required period starting from a relatively early time at aninitial stage of a turn of the vehicle, and of a situation in front ofthe vehicle where the traveling direction of the vehicle can be easilyrecognized at a relatively early time at a late stage of the turn of thevehicle. Thus, the vehicle periphery monitor 20 in accordance with thesecond embodiment informs the driver well in advance of a peripheralsituation of the vehicle to which the driver has to pay attention, andthus makes it possible to keep the driver alert and to ensure safedriving during a turn.

Further, in the case where a hysteresis is set as to a threshold of aparameter for shifting the photo image displayed by the indicatordisplay 40, even if the turning of the vehicle has been completed, forexample, because the steering angle δ that has reached the predeterminedangle δ1 does not reach the predetermined angle δ2 afterwards, thelateral photo image filmed by the side camera 34 may remain displayed.Hence, according to the second embodiment, with a view to avoiding suchan inconvenience, if a predetermined time has elapsed after the start ofthe display of the lateral photo image filmed by the side camera 34, thelateral photo image ceases to be displayed, and the front photo imagefilmed by the front camera 32 is displayed. Hence, according to thesecond embodiment, the lateral photo image filmed by the side camera 34is prevented from unduly remaining displayed, without requiring thedriver to perform any operation.

It is to be noted in the aforementioned second embodiment that thepredetermined angle δ1 corresponds to “the first angle” mentioned in theclaims, that the predetermined angle δ2 corresponds to “the secondangle” mentioned in the claims, that the predetermined time T0corresponds to “the predetermined time” mentioned in the claims.

In the aforementioned second embodiment, after the display of thelateral photo image filmed by the side camera 34 has been started, thelateral photo image remains displayed until the steering angle δ isreduced or until a predetermined time elapses. However, while thelateral photo image remains displayed, it is also appropriate that thephoto image displayed by the indicator display 40 be temporarily shiftedto the front photo image filmed by the front camera 32, for example,every time a certain period elapses or every time the vehicle covers acertain distance. According to this construction, without requiring thedriver to perform any operation, the driver is temporarily informed of asituation in front of the vehicle while being informed of a situationbeside the vehicle. Thus, the driver can be prevented from focusing toomuch attention on the area beside the vehicle, whereby it becomespossible to guarantee much safer driving while making a turn. That is,the lateral photo image can be prevented from remaining displayed,without imposing an operational burden on the driver.

Next, a third embodiment of the invention will be described withreference to FIG. 7 as well as FIGS. 1 and 2.

when starting the vehicle from a stopped state, the driver first has toconfirm, just before takeoff, a situation of an area toward which thevehicle is to travel. Thus, the third embodiment is designed to help thedriver check safety by causing the indicator display 40 to display aperipheral situation of the vehicle as a photo image in the case wherethe vehicle is ready for takeoff, without requiring the driver toperform any operation. In the third embodiment, components identical tothose of the aforementioned construction shown in FIG. 1 are denoted bythe same reference numerals and will not be described again below.

During takeoff of the vehicle as well, as has been described above inthe second embodiment, it is appropriate, from the standpoint ofinforming the driver of a situation to which the driver has to payattention in the traveling direction of the vehicle, that a front photoimage filmed by the front camera 32 be displayed by the indicatordisplay 40 if the steering angle δ is small, and that a lateral photoimage filmed by the side camera 34 be displayed by the indicator display40 if the steering angle δ is large.

Further, in the third embodiment, the vehicle has rear wheels RL, RR asnon-turnable wheels and front wheels FL, FR as turnable wheels asdescribed above. Hence, when the vehicle moves backwards by making aturn, the front portion of the vehicle on the turn-wise outer sideswings outwards considerably and thus causes a substantial differencebetween the tracks of the turn-wise outer wheels. Thus, when the vehiclestarts backwards while making a turn, it is appropriate from thestandpoint of checking safety that the driver be informed of a situationbeside the vehicle by causing the indicator display 40 to display alateral photo image filmed by the side camera 34.

FIG. 7 shows an exemplary flowchart of a control routine that isexecuted by the computer 22 in the third embodiment so as to realize theaforementioned functions. The routine shown in FIG. 7 is repeatedlystarted every time processings thereof are terminated. If the routineshown in FIG. 7 is started, the processing in step 200 is firstperformed.

In step 200, it is determined on the basis of an output signal of theshift position sensor 24 whether or not the gear-shift lever has beenshifted from a neutral position “N”, a parking position “P”, or thereverse position “R” to a forward position “D”. If this condition hasbeen fulfilled, it can be determined that the vehicle is allowed to moveforwards. Thus, the necessity to inform the driver of a situation behindthe vehicle is not vital. Accordingly, if the determination is thusmade, the processing in step 202 is then performed.

In step 202, it is determined whether or not the steering angle δ of thesteering wheel detected by means of the steering angle sensor 26 issmaller than a predetermined angle δ3. It is to be noted herein that thepredetermined angle δ3 is a steering angle δ from which it can bedetermined that the lateral photo image filmed by the side camera 34covers a larger area in the traveling direction of the vehicle than thefront photo image filmed by the front camera 32. If a relationship δ<δ3has been established as a result, it is possible to determine that thevehicle starts moving forwards almost rectilinearly. Accordingly, if thedetermination is thus made, the processing in step 204 is thenperformed.

In step 204, the processing of causing the indicator display 40 todisplay the front photo image filmed by the front camera 32 as to thearea in front of the vehicle is performed. If the processing in step 204is performed, the indicator display 40 thereafter displays a sight infront of the vehicle. If the processing in step 204 is terminated, theprocessing in step 206 is performed.

In step 206, it is determined whether or not a time T, that has elapsedafter the start of the display of the front photo image filmed by thefront camera 32 in the aforementioned step 204 has reached apredetermined time T_(F0). It is to be noted herein that thepredetermined time T_(F0) is set as a time that enables the driver tobroadly grasp an overall situation in front of the vehicle. If thevehicle periphery monitor is equipped with a speaker in this case, it isalso appropriate that the driver be informed through audio guidance ofthe fact that a photo image filmed by the camera has been displayed bythe indicator display 40. The processing in step 206 is repeatedlyperformed until it is determined that a relationship T_(F)≧T_(F0) hasbeen established. If it is determined as a result that the relationshipT_(F)≧T_(F0) has been established, the processing in step 208 is thenperformed, and the photo image displayed by the indicator display 40ceases to be displayed. If the processing in step 208 is terminated, thepresent routine is terminated.

On the other hand, in the aforementioned step 202, if a relationshipδ<δ3 has not been established, that is, if a relationship δ≧δ3 has beenestablished (i.e., if the steering wheel has been considerably turnedcounterclockwise), it can be determined that the vehicle starts movingforwards while making a sharp left turn. In this case, it is appropriateto display a photo image filmed by the side camera 34 where thetraveling direction of the vehicle can be easily recognized.Accordingly, if the determination is thus made, the processing in step210 is then performed.

In step 210, the processing of causing the indicator display 40 todisplay the lateral photo image filmed by the side camera 34 as to thearea beside the vehicle is performed. If the processing in step 210 isperformed, a sight beside the vehicle is represented on the indicatordisplay 40. If the processing in step 210 is terminated, the processingin step 212 is performed.

In step 212, it is determined whether or not a time T_(S) that haselapsed after the start of the display of the lateral photo image filmedby the side camera 34 in the aforementioned step 210 has reached apredetermined time T_(S0). It is to be noted herein that thepredetermined time T_(S0) is set as a time that enables the driver tobroadly grasp an overall situation beside the vehicle. The processing instep 212 is repeatedly performed until it is determined that arelationship T_(S)≧T_(S0) has been established. If it is determined as aresult that the relationship T_(S)≧T_(S0) has been established, theaforementioned processing in step 208 is then performed, and the photoimage displayed by the indicator display 40 ceases to be displayed.

Further, if it is determined in the aforementioned step 200 that thepredetermined condition has not been fulfilled, the processing in step214 is then performed.

In step 214, it is determined on the basis of an output signal of theshift position sensor 24 whether or not the gear-shift lever has beenshifted from the neutral position “N”, the parking position “P”, or theforward position “D” to the reverse position “R”. If this condition hasbeen fulfilled, it can be determined that the vehicle is allowed to movebackwards. Therefore, the necessity to inform the driver of a situationin front of the vehicle is vital. Accordingly, if the determination isthus made, the processing in step 214 is then performed. On the otherhand, if it is determined that this condition has not been fulfilled,the processing in the aforementioned step 200 is performed.

In step 216, it is determined whether or not a steering angle −δ of thesteering wheel detected by means of the steering angle sensor 26 issmaller than a predetermined angle −δ4. As described above, the steeringangle δ assumes a positive value if the steering wheel has been turnedcounterclockwise, whereas the steering angle δ assumes a negative valueif the steering wheel has been turned clockwise. The predetermined angle−δ4 is a steering angle δ from which it can be determined that adifference between the turn-wise outer wheels is caused to such anextent that the front portion of the vehicle on the turn-wise outer sidecan be estimated to swing outwards considerably. If a relationship−δ<−δ4 has not been established as a result, that is, if a relationship−δ≧−δ4 has been established (i.e., if the steering wheel has beenconsiderably turned clockwise), it is possible to determine that thevehicle starts moving backwards while making a sharp right turn, and itis appropriate to display a photo image filmed by the side camera 34.Thus, if it is determined that the relationship −δ<−δ4 has not beenestablished, the aforementioned processing in step 210 is performed, andthe indicator display 40 thereafter displays a sight beside the vehicle.On the other hand, if the relationship −δ<−δ4 has been established, itis possible to determine that the vehicle moves backwards almostrectilinearly. Thus, if it is determined that the relationship −δ<−δ4has been established, the processing in step 218 is then performed.

In step 218, the processing of displaying the rear photo image filmed bythe back camera 30 as to the area behind the vehicle is performed. Ifthe processing in step 218 is performed, the indicator display 40thereafter displays a sight behind the vehicle. If the processing instep 218 is terminated, the processing in step 220 is performed.

In step 220, it is determined on the basis of an output signal of theshift position sensor 24 whether or not the gear-shift lever has beenshifted from the reverse position “R” to another position. If thegear-shift lever is maintained in the reverse position “R”, there is anextensive area behind the vehicle which is invisible from the driver.Hence, it is appropriate that the rear photo image filmed by the backcamera 30 remain displayed. On the other hand, if the gear-shift leverhas been shifted from the reverse position “R” to another position, thenecessity to display the rear photo image diminishes. Accordingly, theprocessing in step 220 is repeatedly performed until it is determinedthat the aforementioned condition has been fulfilled. If it isdetermined that the condition has been fulfilled, the aforementionedprocessing in step 208 is then performed, whereby the photo imagedisplayed by the indicator display 40 ceases to be displayed.

According to the aforementioned routine shown in FIG. 7, under thesituation in which the vehicle starts moving forwards, the front photoimage filmed by the front camera 32 can be displayed by the indicatordisplay 40 if the steering angle of the steering wheel is small, and thelateral photo image filmed by the side camera 34 can be displayed if thesteering angle is large. Further, under the situation in which thevehicle starts moving backwards, the rear photo image filmed by the backcamera 30 can be displayed by the indicator display 40 if the steeringangle of the steering wheel is small, and the lateral photo image filmedby the side camera 34 can be displayed by the indicator display 40 ifthe steering angle is large.

According to this construction, without causing an increase inoperational burden or a reduction in visibility to the driver, thedriver can be informed of a situation in front of the vehicle where thetraveling direction of the vehicle can be easily recognized if thesteering angle δ is small during forward takeoff, and of a situationbeside the vehicle where the traveling direction of the vehicle can beeasily recognized if the steering angle δ is large during forwardtakeoff. Further, the driver can be informed of a situation behind thevehicle where the traveling direction of the vehicle can be easilyrecognized if the steering angle δ is small during backward takeoff, andof a situation beside the vehicle where the periphery of a regioncorresponding to a great difference between the turn-wise outer wheelsis projected if the steering angle δ is large during backward takeoff.

Thus, according to the third embodiment, the driver can be adequatelyinformed of a peripheral situation of the vehicle to which the driverhas to pay attention during takeoff (a situation beside the vehicle asan invisible area in particular) in accordance with a running state ofthe vehicle. Thus, the vehicle periphery monitor 20 in accordance withthe third embodiment makes it possible to keep the driver alert duringtakeoff and to cause the driver to check the safety of an areasurrounding the vehicle during takeoff.

Further, according to the third embodiment, the front photo image filmedby the front camera 32 and the lateral photo image filmed by the sidecamera 34 cease to be displayed if the predetermined period has elapsedsince the start of the display thereof. In this construction, the driverdoes not focus too much attention on the screen of the indicator display40. Thus, safe driving of the vehicle based on the operation by thedriver can be reliably ensured.

It is to be noted in the aforementioned third embodiment that thecomputer 22 performs the processings in step 200 or 214 and step 202 or216 in the aforementioned routine shown in FIG. 7, corresponding to “thecontroller” mentioned in the claims.

In the aforementioned third embodiment, the front photo image filmed bythe front camera 32 and the lateral photo image filmed by the sidecamera 34 cease to be displayed if the predetermined period has elapsedsince the start of the display thereof. However, it is also appropriatethat those photo images cease to be displayed not only in the case wherethe predetermined time has elapsed but also in the case where thevehicle has covered a predetermined distance, where the vehicle speedSPD has reached a predetermined vehicle speed, or the like. It is notabsolutely required that those photo images cease to be displayed. It isalso appropriate that the photo image displayed by the indicator display40 be shifted to the front photo image filmed by the front camera 32 inthe case where a predetermined time has elapsed, where the vehicle hascovered a predetermined distance, or the like.

Next, a fourth embodiment of the invention will be described withreference to FIG. 8 as well as FIGS. 1 and 2.

In the aforementioned third embodiment, the photo image displayed by theindicator display 40 is changed in accordance with the steering angle δof the steering wheel during takeoff of the vehicle. On the other hand,in the fourth embodiment, photo images filmed by the cameras 30 to 34are displayed by the indicator display 40 in a predetermined orderduring takeoff of the vehicle. According to this construction, withoutcausing an increase in operational burden or a reduction in visibilityto the driver, the driver is broadly informed of a peripheral situationof the vehicle. Thus, by urging the driver to pay attention to aninvisible area, the confirmation of safety in the periphery of thevehicle during takeoff thereof can be ensured. In the fourth embodiment,components identical to those of the aforementioned construction shownin FIG. 1 are denoted by the same reference numerals and will not bedescribed again below.

FIG. 8 shows an exemplary flowchart of a control routine that isexecuted by the computer 22 in the fourth embodiment so as to realizethe aforementioned functions. The routine shown in FIG. 8 is repeatedlystarted every time processings thereof are terminated. If the routineshown in FIG. 8 is started, the processing in step 250 is firstperformed.

In step 250, it is determined on the basis of an output signal of theshift position sensor 24 whether or not the gear-shift lever has beenshifted from the neutral position “N”, the parking position “P”, or thereverse position “R” to the forward position “D”, or whether or not thegear-shift lever has been shifted from the neutral position “N”, theparking position “P”, or the forward position “D” to the reverseposition “R”. The processing in step 250 is repeatedly performed untilit is determined that the aforementioned condition has been fulfilled.If it is determined as a result that the aforementioned condition hasbeen fulfilled, the processing in step 252 is performed.

In step 252, the processing of displaying a front photo image filmed bythe front camera 32 as to an area in front of the vehicle on theindicator display 40 is performed. If the processing in step 252 isperformed, the indicator display 40 thereafter displays a sight in frontof the vehicle. If the processing in step 252 is terminated, theprocessing in step 254 is performed.

In step 254, it is determined whether or not the time T_(F) that haselapsed after the start of the display of the front photo image filmedby the front camera 32 in the aforementioned step 252 has reached apredetermined time T_(F1). It is to be noted herein that thepredetermined time T_(F1) is set as a time that enables the driver tobroadly grasp an overall situation in front of the vehicle. If thevehicle periphery monitor is equipped with a speaker in this case, it isalso appropriate that the driver be informed through audio guidance ofthe fact that a photo image filmed by the camera has been displayed bythe indicator display 40. The processing in step 254 is repeatedlyperformed until it is determined that a relationship T_(F)≧T_(F1) hasbeen established. If it is determined as a result that the relationshipT_(F)≧T_(F1) has been established, the processing in step 256 is thenperformed.

In step 256, the processing of causing the indicator display 40 todisplay a lateral photo image filmed by the side camera 34 as to an areabeside the vehicle is performed. If the processing in step 256 isperformed, the indicator display 40 thereafter displays a sight besidethe vehicle. If the processing in step 256 is terminated, the processingin step 258 is performed.

In step 258, it is determined whether or not a time T_(S1) that haselapsed after the start of the display of the lateral photo image filmedby the side camera 34 in the aforementioned step 256 has reached apredetermined time T_(S1). It is to be noted herein that thepredetermined time T_(S1) is set as a time that enables the driver tobroadly grasp an overall situation beside the vehicle. The processing instep 258 is repeatedly performed until it is determined that arelationship T_(S)≧T_(S1) has been established. If it is determined as aresult that the relationship T_(S)≧T_(S1) has been established, theaforementioned processing in step 260 is then performed.

In step 260, the processing of causing the indicator display 40 todisplay a rear photo image filmed by the back camera 30 as to an areabehind the vehicle is performed. If the processing in step 260 isperformed, a sight behind the vehicle is thereafter represented on theindicator display 40. If the processing in step 260 is terminated, theprocessing in step 262 is performed.

In step 262, it is determined whether or not a time T_(B) that haselapsed after the start of the display of the rear photo image filmed bythe back camera 30 in the aforementioned step 260 has reached apredetermined time T_(B1). It is to be noted herein that thepredetermined time T_(B1) is set as a time that enables the driver tobroadly grasp an overall situation behind the vehicle. The processing instep 262 is repeatedly performed until it is determined that arelationship T_(B)≧T_(B1) has been established. If it is determined as aresult that the relationship T_(B)≧T_(B1) has been established, theprocessing in step 264 is performed.

In step 264, the photo image displayed by the indicator display 40ceases to be displayed. If the processing in step 264 is terminated, thepresent routine is terminated.

According to the aforementioned routine shown in FIG. 8, the front photoimage filmed by the front camera 32, the lateral photo image filmed bythe side camera 34, and the rear photo image filmed by the back camera30 can be temporarily displayed in this order by the indicator displayunder the situation in which the vehicle takes off. According to thisconstruction, the driver can be broadly informed of a peripheralsituation of the vehicle during takeoff, without causing an increase inoperational burden or a reduction in visibility to the driver. Thus,according to the vehicle periphery monitor 20 in accordance with thefourth embodiment, it is possible to cause the driver to adequatelycheck safety in starting the vehicle.

In the fourth embodiment, after all the photo images filmed by thecameras 30 to 34 have been displayed, no more photo image is displayedby the indicator display 40. In this construction, as in the case of theaforementioned third embodiment, the driver does not focus too muchattention on the screen of the indicator display 40. Thus, safe drivingof the vehicle based on the operation by the driver can be reliablyensured.

It is to be noted in the aforementioned fourth embodiment that the frontphoto image filmed by the front camera 32 and the rear photo imagefilmed by the back camera 30 correspond to “the second photo image”mentioned in the claims.

In the aforementioned fourth embodiment, after all the photo imagesfilmed by the cameras 30 to 34 have been displayed, no more photo imageis displayed by the indicator display 40. However, it is alsoappropriate that a photo image representing a situation in the travelingdirection of the vehicle be displayed by the indicator display 40.

In the aforementioned fourth embodiment, the photo image to betemporarily displayed by the indicator display 40 is shifted in theorder of the front photo image filmed by the front camera 32, thelateral photo image filmed by the side camera 34, and the rear photoimage filmed by the back camera 30. However, it is not absolutelyrequired that the photo image displayed by the indicator display 40 beshifted in this order. That is, it is also appropriate that the photoimage displayed by the indicator display 40 be shifted in another order.Further, it is not invariably required that the photo image displayed bythe indicator display 40 be shifted in a predetermined order. The orderin which those photo images are displayed may be changed in accordancewith the shift position or the steering angle δ.

In the aforementioned third and fourth embodiments, it is determinedwhether or not the vehicle has become ready to take off, depending onwhether or not the shift position has changed according to apredetermined pattern on the basis of an output signal of the shiftposition sensor 24. However, the invention is not limited to thisconstruction. It is also appropriate to determine whether or not thevehicle has become ready to take off, depending on whether or not abraking operation is being performed in a stopped state of the vehicle.In this construction, if the vehicle has temporarily stopped through abraking operation after having traveled for a while, the vehicle isregarded as having become ready to take off, and the photo images filmedby the cameras 30 to 34 are displayed by the indicator display 40.Hence, it is possible to permit the driver to check safety duringtakeoff of the vehicle. In this case, it is also appropriate that thephoto image be displayed by the indicator display 40 if a predetermineddelay time has elapsed after temporary stoppage of the vehicle through abraking operation, which follows a running state of the vehicle.

According to the aforementioned first to fourth embodiments, in thearrangement wherein the back camera 30 for filming a rear area, thefront camera 32 for filming a front area, and the side camera 34 forfilming a lateral area are disposed in the rear, front, and lateralportions of the vehicle body respectively, the rear photo image filmedby the back camera 30 is displayed by the indicator display 40 if thedriver is informed of a situation behind the vehicle, the lateral photoimage filmed by the side camera 34 is displayed by the indicator display40 if the driver is informed of a situation beside the vehicle, and thefront photo image filmed by the front camera 32 is displayed by theindicator display 40 if the driver is informed of a situation in frontof the vehicle. However, the invention is not limited to thisconstruction. That is, it is also appropriate that one camera capable offilming the entire area surrounding the vehicle be disposed in thevehicle and that the photo image to be displayed by the indicatordisplay 40 be shifted from one area to another by orienting the camerain a direction of which the driver is to be informed.

In the aforementioned first to fourth embodiments, the vehicle peripherymonitor 20 is used to help the driver drive the vehicle having the rearwheels RL, RR as non-turnable wheels and the front wheels FL, FR asturnable wheels. However, the vehicle periphery monitor 20 can also beused to help the driver drive a vehicle having front wheels FL, FR asnon-turnable wheels and rear wheels RL, RR as turnable wheels or avehicle having front and rear wheels as turnable wheels.

Furthermore, in the aforementioned first to fourth embodiments, the sidecamera 34 is disposed only in the lateral portion on the other side ofthe driver seat, and the photo image filmed by the side camera 34 can bedisplayed by the indicator display 40. Hence, according to theseembodiments, the driver can be informed of a situation beside thevehicle on the other side of the driver seat. The area beside thevehicle on the other side of the driver seat is less visible from thedriver than the area beside the vehicle on the side of the driver seat.It is not absolutely required that the side camera 34 be disposed in thelateral portion on the other side of the driver seat. That is, it isalso appropriate that the side camera 34 be disposed in the lateralportion on the side of the driver seat and that the indicator display 40be capable of displaying photo images filmed by the side camera 34. Inthis construction, without causing an increase in operational burden ora reduction in visibility to the driver, the driver can be adequatelyinformed of a peripheral situation of a portion of the vehicle 80 whichtends to come into contact with something, namely, of a peripheralsituation of the vehicle which is wanted by the driver and to whichattention has to be paid, if the driver has requested a lateral photoimage filmed by the side camera to be displayed for the purpose ofchecking safety during a right turn or if the driver has considerablyturned the steering wheel to the right. As a result, it is possible tokeep the driver alert in driving safely during a right turn.

In the aforementioned first to fourth embodiments, the lateral photoimage may include a photo image representing a continuous area extendingfrom the lateral portion to the front portion of the vehicle in additionto a photo image representing the lateral portion of the vehicle.Further, in the aforementioned first to fourth embodiments, the steeringangle that is actually relevant to the steering wheel is regarded as thesteering angle of the vehicle. However, it is also appropriate that asteering that is actually relevant to the wheels be regarded as thesteering angle of the vehicle.

1. A vehicle periphery monitor comprising: an indicator display that canselectively display a first photo image representing an area beside avehicle or a second photo image representing an area different from thearea beside the vehicle; and a controller that automatically shifts thedisplay of one of the first and second photo images on the indicatordisplay to the other upon fulfillment of a predetermined condition,wherein the controller uses a deflection angle of the vehicle as thepredetermined condition and makes a shift between the first and secondphoto images depending on whether or not the deflection angle hasreached a predetermined angle.
 2. The vehicle periphery monitoraccording to claim 1, wherein the controller makes a shift to the secondphoto image if it is determined that the deflection angle has reachedthe predetermined angle while the indicator display is displaying thefirst photo image.
 3. The vehicle periphery monitor according to claim1, wherein the controller determines whether or not the deflection anglehas reached the predetermined angle, on the assumption that the vehicleis in a reference state when the indicator display starts displaying thefirst photo image.
 4. The vehicle periphery monitor according to claim1, wherein the controller determines whether or not the deflection anglehas reached the predetermined angle, on the basis of a yaw anglegenerated by the vehicle.
 5. The vehicle periphery monitor according toclaim 1, wherein the controller determines whether or not the deflectionangle has reached the predetermined angle, on the basis of arelationship between a steering angle generated by the vehicle and arunning distance.
 6. The vehicle periphery monitor according to claim 1,wherein the controller determines that the deflection angle has reachedthe predetermined angle, if the vehicle has continuously covered apredetermined distance with the steering angle being equal to or largerthan a predetermined angle.
 7. A method of monitoring a periphery of avehicle having an indicator display and that selectively displays afirst photo image representing an area beside the vehicle or a secondphoto image representing an area different from the first photo image,comprising the step of: automatically causing the indicator display toshift from displaying one of the first and second photo images to theother upon fulfillment of a predetermined condition, wherein adeflection angle of the vehicle is used as the predetermined condition,and a shift between the first and second photo images is made dependingon whether or not the deflection angle has reached a predeterminedangle.
 8. The method according to claim 7, wherein a shift to the secondphoto image is made if it is determined that the deflection angle hasreached the predetermined angle while the first photo image is displayedby the indicator display.
 9. The method according to claim 7, wherein itis determined whether or not the deflection angle has reached thepredetermined angle, on the assumption that the vehicle is in areference state when the indicator display starts displaying the firstphoto image.
 10. The method according to claim 7, wherein it isdetermined whether or not the deflection angle has reached thepredetermined angle, on the basis of a yaw angle generated by thevehicle.
 11. The method according to claim 7, wherein it is determinedwhether or not the deflection angle has reached the predetermined angle,on the basis of a relationship between a steering angle generated by thevehicle and a running distance.
 12. The method according to claim 7,wherein it is determined that the deflection angle has reached thepredetermined angle, if the vehicle has continuously covered apredetermined distance with the steering angle being equal to or largerthan a predetermined angle.